Nishanth Menon <nm@xxxxxx> writes:
> Voltage values can get confusing in meaning with various SmartReflex
> classes being active. Depending on the class used, the actual voltage
> selected might be a variant. For example:
> With SmartReflex AVS class 3:
> a) If we don't have SR enabled, we will go to volt_nominal.
> b) If have SR enabled, we go to volt_nominal, then enable SR and
> expect it to adjust voltage. We don't really care about the
> resultant voltage.
> Essentially, when we ask voltage layer to scale to voltage x for OPP
> y, it always means x is the nominal voltage for OPP y.
>
> Now, once we introduce SmartReflex AVS class 1.5:
> a) If you are booting for the first time OR if you never enabled SR
> before, we always go to volt_nominal.
> b) If you enable SR and the OPP is calibrated, we will not enable SR
> again when that OPP is accessed anymore, but when we set voltage for
> an OPP, the voltage achieved will be volt_calibrated.
> c) If recalibration timeout triggers or SR is disabled after a
> calibration, the calibrated values are not valid anymore, at this point,
> setting the voltage will mean volt_dynamic_nominal.
> So, depending on which state the system is at, voltage for that OPP
> we are setting has not 1 single value anymore, but 3 possible valid
> values.
>
> For upper layers(DVFS/cpufreq OMAP SoC layers) to use voltage values, it
> will need to know which type of voltage AVS strategy is being used and
> the corresponding system state from voltage layer perspective. This
> would replicate the role of voltage layer, SmartReflex AVS in the upper
> layers and make the corresponding implementations complex.
>
> Since each voltage domain contains a set of volt_data structs representing
> a voltage point that is supported for that domain, volt_data is a more
> accurate representation of the voltage point we are interested in going to,
> and the actual translation of this voltage point to the voltage value is
> done inside the voltage layer. Doing this allows the users of the voltage
> layer to be blissfully ignorant of any complexity of the underneath
> layers and simplify the implementation of dependent layers.
>
> Signed-off-by: Nishanth Menon <nm@xxxxxx>
Mostly coding style and/or readability comments below...
> ---
> arch/arm/mach-omap2/pm.c | 3 +-
> arch/arm/mach-omap2/smartreflex-class3.c | 3 +-
> arch/arm/mach-omap2/voltage.c | 75 +++++++++++++++++-------------
> arch/arm/mach-omap2/voltage.h | 17 +++++--
> 4 files changed, 59 insertions(+), 39 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/pm.c b/arch/arm/mach-omap2/pm.c
> index 2c3a253..2372744 100644
> --- a/arch/arm/mach-omap2/pm.c
> +++ b/arch/arm/mach-omap2/pm.c
> @@ -209,7 +209,8 @@ static int __init omap2_set_init_voltage(char *vdd_name, char *clk_name,
> goto exit;
> }
>
> - omap_voltage_scale_vdd(voltdm, bootup_volt);
> + omap_voltage_scale_vdd(voltdm,
> + omap_voltage_get_voltdata(voltdm, bootup_volt));
coding style: to avoid wrapping (which IMO affects readabiliyt), assign
volt_data to it's own variable then pass it to scale_vdd.
> return 0;
>
> exit:
> diff --git a/arch/arm/mach-omap2/smartreflex-class3.c b/arch/arm/mach-omap2/smartreflex-class3.c
> index f438cf4..2ee48af 100644
> --- a/arch/arm/mach-omap2/smartreflex-class3.c
> +++ b/arch/arm/mach-omap2/smartreflex-class3.c
> @@ -15,7 +15,8 @@
>
> static int sr_class3_enable(struct voltagedomain *voltdm)
> {
> - unsigned long volt = omap_voltage_get_nom_volt(voltdm);
> + unsigned long volt = omap_get_operation_voltage(
> + omap_voltage_get_nom_volt(voltdm));
readability/wrapping
Also, the name of the new function doesn't follow the naming convention
of the rest of the voltage layer: e.g. omap_voltage_...
> if (!volt) {
> pr_warning("%s: Curr voltage unknown. Cannot enable sr_%s\n",
> diff --git a/arch/arm/mach-omap2/voltage.c b/arch/arm/mach-omap2/voltage.c
> index 76bcaee..a12ac1e 100644
> --- a/arch/arm/mach-omap2/voltage.c
> +++ b/arch/arm/mach-omap2/voltage.c
> @@ -58,7 +58,7 @@ static struct dentry *voltage_dir;
>
> /* Init function pointers */
> static int vp_forceupdate_scale_voltage(struct omap_vdd_info *vdd,
> - unsigned long target_volt);
> + struct omap_volt_data *target_volt);
>
> static u32 omap3_voltage_read_reg(u16 mod, u8 offset)
> {
> @@ -164,13 +164,20 @@ static int vp_volt_debug_get(void *data, u64 *val)
> static int nom_volt_debug_get(void *data, u64 *val)
> {
> struct omap_vdd_info *vdd = (struct omap_vdd_info *) data;
> + struct omap_volt_data *volt_data;
>
> if (!vdd) {
> pr_warning("Wrong paramater passed\n");
> return -EINVAL;
> }
>
> - *val = omap_voltage_get_nom_volt(&vdd->voltdm);
> + volt_data = omap_voltage_get_nom_volt(&vdd->voltdm);
> + if (IS_ERR_OR_NULL(volt_data)) {
> + pr_warning("%s: No voltage/domain?\n", __func__);
> + return -ENODEV;
> + }
> +
> + *val = volt_data->volt_nominal;
>
> return 0;
> }
> @@ -184,7 +191,8 @@ static void vp_latch_vsel(struct omap_vdd_info *vdd)
> unsigned long uvdc;
> char vsel;
>
> - uvdc = omap_voltage_get_nom_volt(&vdd->voltdm);
> + uvdc = omap_get_operation_voltage(
> + omap_voltage_get_nom_volt(&vdd->voltdm));
wrapping
> if (!uvdc) {
> pr_warning("%s: unable to find current voltage for vdd_%s\n",
> __func__, vdd->voltdm.name);
> @@ -302,13 +310,19 @@ static void __init vdd_debugfs_init(struct omap_vdd_info *vdd)
>
> /* Voltage scale and accessory APIs */
> static int _pre_volt_scale(struct omap_vdd_info *vdd,
> - unsigned long target_volt, u8 *target_vsel, u8 *current_vsel)
> + struct omap_volt_data *target_volt, u8 *target_vsel,
> + u8 *current_vsel)
> {
> - struct omap_volt_data *volt_data;
> const struct omap_vc_common_data *vc_common;
> const struct omap_vp_common_data *vp_common;
> u32 vc_cmdval, vp_errgain_val;
>
> + if (IS_ERR_OR_NULL(target_volt) || IS_ERR_OR_NULL(vdd) ||
Checking for NULL on arguments passed in is fine, but not sure the error
check here makes any sense.
> + !target_vsel || !current_vsel) {
> + pr_err("%s: invalid parms!\n", __func__);
> + return -EINVAL;
> + }
> +
> vc_common = vdd->vc_data->vc_common;
> vp_common = vdd->vp_data->vp_common;
>
> @@ -332,12 +346,8 @@ static int _pre_volt_scale(struct omap_vdd_info *vdd,
> return -EINVAL;
> }
>
> - /* Get volt_data corresponding to target_volt */
> - volt_data = omap_voltage_get_voltdata(&vdd->voltdm, target_volt);
> - if (IS_ERR(volt_data))
> - volt_data = NULL;
> -
> - *target_vsel = vdd->pmic_info->uv_to_vsel(target_volt);
> + *target_vsel = vdd->pmic_info->uv_to_vsel(
> + omap_get_operation_voltage(target_volt));
wrapping
> *current_vsel = vdd->read_reg(prm_mod_offs, vdd->vp_data->voltage);
>
> /* Setting the ON voltage to the new target voltage */
> @@ -347,22 +357,21 @@ static int _pre_volt_scale(struct omap_vdd_info *vdd,
> vdd->write_reg(vc_cmdval, prm_mod_offs, vdd->vc_data->cmdval_reg);
>
> /* Setting vp errorgain based on the voltage */
> - if (volt_data) {
> - vp_errgain_val = vdd->read_reg(prm_mod_offs,
> - vdd->vp_data->vpconfig);
> - vdd->vp_rt_data.vpconfig_errorgain = volt_data->vp_errgain;
> - vp_errgain_val &= ~vp_common->vpconfig_errorgain_mask;
> - vp_errgain_val |= vdd->vp_rt_data.vpconfig_errorgain <<
> - vp_common->vpconfig_errorgain_shift;
> - vdd->write_reg(vp_errgain_val, prm_mod_offs,
> - vdd->vp_data->vpconfig);
> - }
> + vp_errgain_val = vdd->read_reg(prm_mod_offs,
> + vdd->vp_data->vpconfig);
> + vdd->vp_rt_data.vpconfig_errorgain = target_volt->vp_errgain;
> + vp_errgain_val &= ~vp_common->vpconfig_errorgain_mask;
> + vp_errgain_val |= vdd->vp_rt_data.vpconfig_errorgain <<
> + vp_common->vpconfig_errorgain_shift;
> + vdd->write_reg(vp_errgain_val, prm_mod_offs,
> + vdd->vp_data->vpconfig);
>
> return 0;
> }
>
> static void _post_volt_scale(struct omap_vdd_info *vdd,
> - unsigned long target_volt, u8 target_vsel, u8 current_vsel)
> + struct omap_volt_data *target_volt, u8 target_vsel,
> + u8 current_vsel)
> {
> u32 smps_steps = 0, smps_delay = 0;
>
> @@ -377,7 +386,7 @@ static void _post_volt_scale(struct omap_vdd_info *vdd,
>
> /* vc_bypass_scale_voltage - VC bypass method of voltage scaling */
> static int vc_bypass_scale_voltage(struct omap_vdd_info *vdd,
> - unsigned long target_volt)
> + struct omap_volt_data *target_volt)
> {
> u32 loop_cnt = 0, retries_cnt = 0;
> u32 vc_valid, vc_bypass_val_reg, vc_bypass_value;
> @@ -429,7 +438,7 @@ static int vc_bypass_scale_voltage(struct omap_vdd_info *vdd,
>
> /* VP force update method of voltage scaling */
> static int vp_forceupdate_scale_voltage(struct omap_vdd_info *vdd,
> - unsigned long target_volt)
> + struct omap_volt_data *target_volt)
> {
> u32 vpconfig;
> u8 target_vsel, current_vsel, prm_irqst_reg;
> @@ -675,16 +684,15 @@ ovdc_out:
> * omap_voltage_get_nom_volt() - Gets the current non-auto-compensated voltage
> * @voltdm: pointer to the VDD for which current voltage info is needed
> *
> - * API to get the current non-auto-compensated voltage for a VDD.
> - * Returns 0 in case of error else returns the current voltage for the VDD.
> + * API to get the current voltage data pointer for a VDD.
> */
> -unsigned long omap_voltage_get_nom_volt(struct voltagedomain *voltdm)
> +struct omap_volt_data *omap_voltage_get_nom_volt(struct voltagedomain *voltdm)
> {
> struct omap_vdd_info *vdd;
>
> if (IS_ERR_OR_NULL(voltdm)) {
> pr_warning("%s: VDD specified does not exist!\n", __func__);
> - return 0;
> + return ERR_PTR(-ENODATA);
> }
>
> vdd = container_of(voltdm, struct omap_vdd_info, voltdm);
> @@ -819,18 +827,19 @@ void omap_vp_disable(struct voltagedomain *voltdm)
> * omap_voltage_scale_vdd() - API to scale voltage of a particular
> * voltage domain.
> * @voltdm: pointer to the VDD which is to be scaled.
> - * @target_volt: The target voltage of the voltage domain
> + * @target_volt: The target voltage data for the voltage domain
> *
> * This API should be called by the kernel to do the voltage scaling
> * for a particular voltage domain during dvfs or any other situation.
> */
> int omap_voltage_scale_vdd(struct voltagedomain *voltdm,
> - unsigned long target_volt)
> + struct omap_volt_data *target_volt)
> {
> struct omap_vdd_info *vdd;
>
> - if (IS_ERR_OR_NULL(voltdm)) {
> - pr_warning("%s: VDD specified does not exist!\n", __func__);
> + if (IS_ERR_OR_NULL(voltdm) || IS_ERR_OR_NULL(target_volt)) {
checking for NULL should suffice
> + pr_warning("%s: Bad Params vdm=%p tv=%p!\n", __func__,
> + voltdm, target_volt);
> return -EINVAL;
> }
>
> @@ -856,7 +865,7 @@ int omap_voltage_scale_vdd(struct voltagedomain *voltdm,
> */
> void omap_voltage_reset(struct voltagedomain *voltdm)
> {
> - unsigned long target_uvdc;
> + struct omap_volt_data *target_uvdc;
>
> if (IS_ERR_OR_NULL(voltdm)) {
> pr_warning("%s: VDD specified does not exist!\n", __func__);
> diff --git a/arch/arm/mach-omap2/voltage.h b/arch/arm/mach-omap2/voltage.h
> index e9f5408..6e9acd6 100644
> --- a/arch/arm/mach-omap2/voltage.h
> +++ b/arch/arm/mach-omap2/voltage.h
> @@ -131,25 +131,25 @@ struct omap_vdd_info {
> const struct omap_vfsm_instance_data *vfsm;
> struct voltagedomain voltdm;
> struct dentry *debug_dir;
> - u32 curr_volt;
> + struct omap_volt_data *curr_volt;
> bool vp_enabled;
> u32 (*read_reg) (u16 mod, u8 offset);
> void (*write_reg) (u32 val, u16 mod, u8 offset);
> int (*volt_scale) (struct omap_vdd_info *vdd,
> - unsigned long target_volt);
> + struct omap_volt_data *target_volt);
> };
>
> unsigned long omap_vp_get_curr_volt(struct voltagedomain *voltdm);
> void omap_vp_enable(struct voltagedomain *voltdm);
> void omap_vp_disable(struct voltagedomain *voltdm);
> int omap_voltage_scale_vdd(struct voltagedomain *voltdm,
> - unsigned long target_volt);
> + struct omap_volt_data *target_volt);
> void omap_voltage_reset(struct voltagedomain *voltdm);
> void omap_voltage_get_volttable(struct voltagedomain *voltdm,
> struct omap_volt_data **volt_data);
> struct omap_volt_data *omap_voltage_get_voltdata(struct voltagedomain *voltdm,
> unsigned long volt);
> -unsigned long omap_voltage_get_nom_volt(struct voltagedomain *voltdm);
> +struct omap_volt_data *omap_voltage_get_nom_volt(struct voltagedomain *voltdm);
> struct dentry *omap_voltage_get_dbgdir(struct voltagedomain *voltdm);
> int __init omap_voltage_early_init(s16 prm_mod, s16 prm_irqst_mod,
> struct omap_vdd_info *omap_vdd_array[],
> @@ -181,4 +181,13 @@ static inline struct voltagedomain *omap_voltage_domain_lookup(char *name)
> }
> #endif
>
> +/* convert volt data to the voltage for the voltage data */
> +static inline unsigned long omap_get_operation_voltage(
> + struct omap_volt_data *vdata)
> +{
> + if (IS_ERR_OR_NULL(vdata))
checking for NULL chould suffice
> + return 0;
> + return vdata->volt_nominal;
> +}
> +
> #endif
Also, this function name should follow the naming convention of the rest
of the voltage layer.
Kevin
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